Maintained pressure snap switch



sept. 4, 1951 R. REGER 2,566,534

MAINTAINED PRESSURE SNAP SWITCH FiledSept. 8, 1947 I I n l 25 47 .G l iii 45 l ss/ ai 44 225 JNVENTOR.

,Bw/mvp 76565K.

Patented Sept. 4, 1951 MAINTAINED'TRESSURE SN AI SWITCH Raymond Reger, Anderson, Ind., .assgn'orto vThe Pierce Governor Company, Inc., Anderson, Ind.,

a corporation Application September 8, 1947, Serial No. 772,715

(Cl. Z4- 97) 10 Claims.

This invention relates toa snap action control mechanism.

The chief object of the present invention is to provide a control mechanism that is of snap action type and one wherein the actuating force may be of progressive character but wherein the control is shifted substantially instantaneously accompanied by pressure maintenance up to the instant of shifting and is reversely established immediately after shifting.l

Herein the force -applyingmember is of the to and fro movable type, one form being reciprocable and another oscillatable and one form being manually operable and another power operable and the same is given by way of example only.

The chief feature of the present invention resides in providing two pairs of spaced abutments and 'disposing therebetween in bridging relation an intermediately articulated structure, the control power being applicable thereto between the ends of said structure.

For purposes of illustration the control mechanism is disclosed as of switch type andthe power operable forms thereof are disclosed as'of centrifugal governor actuable character.

.Other objects and features of the invention will be set forth more fully hereinafter.

v The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

In the drawings, Fig. 1 is an elevational View of a centrifugal governor and switch structure controlled thereby, same embodying the invention, the cover for switch structure being omitted, the switch partsbeing illustrated in what might be termed theV normal position.

Fig. 2 is a similar View of the same with parts illustrated in what might be termed the tripped position.

Fig. 3 is a similar View of a modified form of switch structure with parts in the so--called normal position.

vFig. i is a similar view of said modied form of the invention with parts in the so-calledv tripped position.

Fig. 5 is an elevational View of a manually operable switch embodiment of the invention, the cover being removed for clearness.

Fig. 6 is a transverse sectional view taken on line 6-6 of Fig. 5 and in the direction of the arrows.

Fig. '7 is a longitudinal sectional View taken on line 'l-1 of Fig. 5 and in the direction of the arrows.

lthe form of screws.

In. Figs. l and 2 ofl the drawings, lindicates a governor housing to which is suitably secured base il. Within such housing is disposed a convention-al speed responsive structureA comprising fiyballs er weights `rotatable by member llllrprojectng from the housing and at a speedfproportional to the speed of the unit to be controlled if thecontro'l mechanism'is toV be utilized "for such purposes.

Shaft |3 projects beyond the base H and mounts arm M This shaft is moved counterclockwise by the aforesaid weights vwhen theretational speed thereof is suiiicient'to generate sufficient centrifugal force to rock the shaft in opposition to spring l5 having-onefendsecured to' arm extension IfS and' the other endy adj'ustably anchored.

This adjustable anchorage may partake of many forms. Herein, for example, it comprises an angl-e member l1 secured as at I 8 tothe .base and adjustably supporting as at I9 a threaded member 29 having eye 2| yfor the other'end of said spring.' Lock nuts 22 secured saidmember in adjusted positionandv thus determine the force of spring l5` which is to be overcome.

In the vcentrifugal ,governor art this` spring. is commonly termed the load spring and shaftlf3 which partakes of oscillatory movement is'commonly. termed the rocker shaft.

For electrically operable transmission control purpose the speed governor described makes or breaks-a: control circuitat'one critical speedand breaks ormakesrespectively a circuitatf another speed corresponding to speed increase or decrease above or below governed speed.

Ther two'limits are not necessarily vthe same. Normally centrifugal governors hunt o1 surge. To avoid repetitions'reversiblev control at the socalled.` governor speed, the-snap'action of the mechanism now to be described is peculiarly desirable in that positive selective controly is `effected at all'times and maintainedk except at theinstant of shift, as hereinafterpointed outmore specifically.

The'arm I4 aforesaid has secured'to it at 23Y an angular actuator member` 2li-with the. free end 25 longitudinally slotted at 26 andv transversely grooved as at21 toform seatsorpivots. Disposedxin Vthe slot v2li is the 'wire 28 hookedat 29 to one end of spring 33, the other end of which is hooked at 3l to one end of wire 32.

A metallic strap 33 is secured at 34ftof base il. At one end the strap terminatesin spaced ears 35 which adjustably support stops 36v in These constitute onerpairfof in Figs. 3 and 4.

spaced abutments. Disposed therebetween and bearable upon one or the other of said abutments is strap 31 to which at 38 is secured or hooked the other end of wire 28. One end of said strap 31 is slotted and the legs seat in the seats 21 aforesaid.

The other end of strap 33 terminates in transverse end 39 apertured at 40 to accommodate tension wire 32. The remote face of end 39 is notched at 4| to form seats for the slotted adjacent end of strap 42 to which, remote from' its seated end, as at 43, is anchored the other end of said wire 32.

Carried by base I| are two alignedA members 44 with spaced parallel ears 45 constituting a second pair of spaced abutments and between which the other end of strap member 42 is disposed, the latter bearing upon one or the other of said ears 45.

When the aforesaid is incorporated in a switch structure all or part of the aforesaid snap action mechanism, including arm 39, may be insulated. Herein terminal 46 is provided tothe aforesaid articulated structure and terminal 41 is provided to one of the ears 45. Member 42 at the end between the ears 45 mounts contact In normal position (see Fig. 1) speed is insuflicient to overcome spring I5; hence, the circuit is open between terminals 46 and 41 at contact 48. When the speed is suflicient to rock shaft I3 counterclockwise in opposition to spring I5, the switch assumes the tripped position, see Fig. 2, wherein the terminals 46-41 are now short circuited to complete the control circuit.

When selective dual circuit control is desired another terminal may be provided to the other of members 44. Then arm 42 at 48 selectively short circuits terminal 46 to the terminals on members 44. Fig. 5, incidentally, illustrates such a dual selective or tertiary co-ntrol circuit arrangement.

It will be noted in Fig. 1 the elongated intermediately articulated and tensioned bridging structure bears at opposite ends upon the lower abutment of each pair of abutments while in Fig. 2, the bearing is upon the upper abutment of each pair of abutments.

The free ends of such bridging structure slide, as it were, upon the abutments until the articulating or breaking force is suiiicient to eifect the transfer. Pressure upon the abutments is maintained until the instant the break occurs and is immediately reestablished after the break occurs.

A modified form of the aforesaid is illustrated In this form the bridging structure is simplified and the load spring as well as the lever arm between same and the rocker shaft is adjustable. None of the abutments in this form is adjustable.

Herein abutments |36 comprise pins with inlsulation sleeves and same are carried by base I I I.

Rocker shaft ||3 mounts arm ||4 which carries threaded extension H6. Thereon is adjustably mounted sleeve |||ia and retained by opposed nuts ||6b. Load spring |I5 connects at one end to the sleeve as shown and at the other end to eye |2I on threaded member |20 locked by nuts |22 to the housing wall I|Ia on the base Herein spring |30 has elongated ends |28 and |32 connected at |38 and |43 respectively to strap members |31 and |42 respectively. The angular arm |24 has end |25 notched for seats 4 |21 and slotted as at |26. Transverse member |39 is slotted at |40 and notched for seating strap member |42.

The two spaced abutments |45 are connected as follows; The lower one is electrically connected to terminal |46. This obviously completes the circuit to member |42. The upper abutment |45 insulatably supports contact |453 electrically connected to terminal |41. Members 31 and 42 and |31 and |42 are longitudinally slotted adjacent their fulcrumed ends. Such is shown more clearly in Fig. '7 relative to comparable members 231 and 242.

Operation of the form of the invention shown in Figs. 3 and 4 is substantially the same as that previously described. Note that in the first form the rocker shaft axis is to one side of both fulcrums whereas in the second form the rocker shaft axis is disposed between the fulcrums. The iirst form overall is longer but narrower than the second form. Either may be more advantageously utilized in special installations.

Reference will now be had to Figs. 5 to 7, inclusive wherein a most compact form is illustrated. Herein base 2I| is dened by walls 2| la forming a switch chamber 2| Ib. A cover 2 0 completes the housing. One end wall is thickened at 269 and centrally notched at 20911. Seated in the confronting walls of said notch are contacts 25,5 carried by pins 246 extending to the exterior and mounting terminals 241.

At the opposite end of the chamber and at the junction or" that end wall With the side walls are the other pair of spaced abutments 236. Strap members 231 and 242 are connected at 238 and 243 respectively to opposite elongated ends 228 and 232 respectively of the spring 230.

Slidably supported in aligned slots 2m is the reciprocatory member 225 having elongated slot 225 therein and angular or V-offset portion 221, same serving as a seat or ulcrum for the longitudinally slotted member 231. The slot therein and slot 226 accommodate the spring end 228.

Exteriorly of the housing is terminal 246 and pin or rivet 233 secures the same to the housing as well as angular member 23.9 notched -at 240 and V-formed at 24| to seat or fulcrum the adjacent end of the longitudinally slotted member 242.

In this form dual selective or tertiary control is provided for. In this form the power application is reciprocatory instead of oscillatory. It also is applied substantially tranverse to the bridging structure, and like the other forms the power is applied through one fulcrum providing member. As before the bridging structure contacts either the upper or the lower pairs of the abutments, see Fig. 5. The operation of this form is substantially like that previously described.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. Mechanism suitable for valve and switch control purposes comprising in combination a pair of spaced abutments, a second pair of spaced abutments, the two pairs beingl spaced apart, an elongated multiple pair of bridging type articulated spring structures having substantially free ends disposed between the respective pairs of abutment's and comprising a. pair of longitudinally disposed abutment contacting elements, a force applying member associated with the said spring structure between the ends thereof for shifting the ends thereof for control purposes, a

, pair of fulcrums for the adjacent ends of said elements and having a, tension connection between said elements, one of said fulcrums being stationary and the other being movable by the force applying member and in a direction generally transversely of the direction of elongation of said springstructure.

2. Mechanism as dened by claim 1 wherein the said adjacent ends are spaced apart.

3. Mechanism as defined by claim 2 wherein the force applying member is mounted for to and fro movement and to one side of said adjacent ends.

4. Mechanism as dened by claim 2 wherein the force applying member is mounted for to and fro movement and between said adjacent ends.

5. Mechanism as dened by claim 2 wherein the force applying member is mounted for to and fro movement and coincident with one ofvsaid adjacent ends.

6. Mechanism as defined by claim 1 wherein the force applying member includes a fulcrum providing portion for one of said elements.

7. Mechanism as dened by claim 6 wherein the force applying member is movable by centrifugal force in one direction through a lever arm responsive to such force and a spring constrains that leverarm toward the other direction.

8. Mechanism as deiined by claim '7 wherein an adjustable support is provided for one end of the spring for adjusting the force thereof.

9. Mechanism as dened by claim 7 wherein an adjustable connection is interposed between the lever arm and spring for adjusting the leverage of said arm.

10. Mechanism as defined by claim 7 wherein an adjustable connection is interposed between the lever arm and one end of the spring for leverage adjustment and an adjustable anchorage is provided'for the other end of the spring for spring force adjustment. 1

RAYMOND REGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date l Re. 17,646 Johnson Apr. 22, 1930 1,372,331 Bolzer Mar. 22, 1921 2,194,533 Van Dyke Mar. 26, 1940 2,360,128 Hausler Oct. 10, 1944 

